Do you use chisel or semi chisel for cutting black locust? I was using the 20" bar on the 261 which was full chisel. Switch to the 16" bar, chain cut better and was semi chisel. The wood was semi ground contact with bark falling off. I have little experience cutting BL and have been using full chisel. Most of what ive cut has been blow over dead with bark on.
Depends on how dirty it is. Full chisel will cut it fine, but might only last a few cuts if it’s dirty, same with any wood. Your semi was probably just sharper when you swapped.
16” bar on that power head was likely just pulling easier. IIRC 16” bar is about max recommended length for a 261. 16-20” bar on 261 would likely pull full chisel , half or full skip really well. Different filing technics help in different species of wood also.
I cut a lot of locust Brad I use both kinds big saws and my top handle use full chisel mid size saw has semi on it locust is just some really tough wood to cut when it has been around for a while the outer layer just under the bark seems to be the most abrasive to the sawmill blades if I run my debarker on the logs even without the bark to just nick that first 1/8 inch it really saves my blades but to your question the semi chisel does hold up a little better because you do not have that point on the cutter which in very abrasive conditions is more fragile and dulls quickly my big saws also use 404 chain which tends to hold its edge better JB
Personally I use squared full chisel on everything. Unless I have a very dirty job/log, then I have one loop of semi to use. It cuts much slower but in the long run, it'll still be cuttin' where I would have to swap chains with the square full chisel. I'll only use it if there is dirt in the bark.
Won't go wrong with semi chisel,IMO. Might be a little slower but,if the wood is hard or dirty,you'll lose the extra time savings filing the chisel chain.I don't think there's really a "wrong" answer to your question.It's largely what you want to accomplish and how.